The San Francisco 49ers have broken ground on the team's $1.2 billion new stadium in the heart of Silicon Valley, with a top team official calling it the National Football League's "smartest" park.

The facility, which the 49ers will occupy for the 2014 season as they abandon the aging Candlestick Park, will have solar panels, locally grown produce and ready access to public transit.

"Welcome to the site of your new home on Sundays," 49ers Chief Executive Jed York told a crowd of about 3,000 people in attendance at the ceremony on the outskirts of Santa Clara, about 40 miles southeast of San Francisco.

"It's going to be the smartest stadium, not the biggest or most expensive," York said.

The bulk of the financing for the stadium comes from an $850 million construction loan obtained by the Santa Clara Stadium Authority, whose board is made up of city council members but is legally separate from the city of 119,000 residents.

The lenders are led by Goldman Sachs Co., Bank of America Corp and U.S. Bancorp.

Some critics have questioned the ability of Santa Clara to handle the project.

"It's not at all clear that the authority will be able to satisfy that debt," Matthew Zinn, an attorney for opponents Santa Clara Plays Fair, said last month.

Voters in Santa Clara backed the NFL stadium in a 2010 referendum.

The decision by the storied football franchise -- which has won five Super Bowls -- to move to a new stadium was celebrated by many of the team's fans, although some expressed dismay that the team would leave San Francisco.

The new facility will have a total seating capacity of 68,500, slightly less than Candlestick Park.

But the park, which for now has been called simply "The New Santa Clara Stadium," will have more square footage and it will use that extra space for wider concourses and hallways, among other things.

Candlestick Park, which opened in 1960 on the edge of the San Francisco Bay, was known for games during windy, cold weather that chilled fans. The Santa Clara stadium nestled next to Great American Amusement Park will be a balmy 75 degrees during the football season.

That may not be enough to console some fans.

"I just wish the 49ers stayed in San Francisco," read a post on Thursday by a person identified as Mike Tagum, on the Facebook page of the 49ers.

San Francisco 49ers linebacker Patrick Willis, 27, was upbeat about the new stadium.

"We're going to make this thing tremendous when it's all said and done," Willis said.